1. Field of Invention
This invention relates to an apparatus and method for collecting blood clots, pieces of plaque and other material that may be accidentally dislodged during interventional procedures in the human vasculature such as arterial and venous angioplasty and stent placement. The invention utilizes a chamber that collects the blood from one sheath or catheter through an aspirating force where the blood can be filtered with removal of thromboembolic debris. The blood can then be recirculated back into the bloodstream through a second access.
2. Background Information
It is common practice today to open occluded (i.e. blocked) or stenotic (i.e. narrowed) blood vessels by inserting a guidewire and then a catheter carrying a balloon shaped distal end and inflating the balloon, which exerts radial force, to press the stenosis outward against the wall of the vessel. This procedure is called balloon angioplasty. Frequently, an implantable metallic stent will be used additionally to provide greater radial strength and longer-term patency.
In order to help deliver the balloon catheters and the stent devices, special guiding catheters or sheaths are used. These guide catheters or sheaths are placed away (or upstream) from the targeted lesion. A guidewire will be advanced past the lesion, allowing the subsequent balloon catheters and stents to be advanced through the guiding catheter or sheath to the target lesion.
During balloon angioplasty and stent placement of the stenotic lesion, there is the risk of dislodging fragments of plaque, thrombus (blood clots) or other material. If the lesion involves arterial circulation, then the particles could flow into smaller vessels in the brain, other organs or extremities resulting in disastrous complications. Likewise, if the lesions involve the venous circulation, then the thromboemboli could flow into the heart and lung possibly resulting in the demise of the patient.
It is the primary purpose of the present invention to provide such a protection. The device can be easily and remotely attached to catheters and sheaths ends. By initiating the device, slow and continuous aspiration will started. Blood will be drawn from the one vessel, filtered and then recirculated into the other vessel. This will allow effective trapping and removal of thromboembolic material.
The device could be attached to the proximal end of special guiding catheters that have a soft occluding balloon used to occlude flow into the vessel. Distal protection could also be provided by the insertion of a small balloon catheter in important branch vessels or past the lesion. Likewise, it can be attached to regular sheath or guiding catheter and provide needed aspiration during key parts of the case.
Benefits of the current invention include low speed rotating paddles or wheels which minimize trauma to individual blood cells which otherwise leads to hemolysis and potential problems such as rhabdomyolysis. Also, since it is a closed loop, there will be little if any blood loss.
The invention will have tremendous benefit in such procedures as carotid artery angioplasty and stent placement, where the incoming loop is attached to the guiding catheter or sheath in the artery and the outgoing system is attached to the venous sheath.
The invention will also have benefit in any procedure with the risk of thromboembolic debris such as other peripheral interventions as well as venous cases.